Israeli officials said the attack took place early Friday and was aimed at sophisticated "game-changing" weapons, but not chemical arms. One official said the target was a shipment of advanced, long-range ground-to-ground missiles but was not more specific.

They did not say where the attack took place, or whether the air force carried out the strike from Lebanese or Syrian airspace.

The Israeli officials spoke on condition of anonymity because they were not authorized to disclose information about a secret military operation to the media.

U.S. officials had earlier confirmed the airstrike but said only that it appeared to have hit a warehouse.

Claiming the strike was aimed at preventing alleged Syrian weapons from reaching Hezbollah in Lebanon, it is unclear how continued salvos from Israel might impact the ongoing civil war in Syria. Of course, given the nature of the missile attack, there is little way to confirm Israel's claims about the nature of the target or, indeed, if their claims about weapons heading to Lebanon are true. Syrian officials had made no public comment about the incident other than to say they could not yet confirm the reports.

Despite the worsening humanitarian situation inside the country, many worry that such behavior by Israel--not to mention an escalated involvement by the US military--could turn Syria's civil war into a regional conflagration.

As Juan Cole explores on his influential blog on Saturday, in addition to Israel, both Turkey and Lebanon are increasingly nervous about the possibility of the conflict spreading.